The present invention relates to a manufacturing apparatus for semiconductor devices and more particularly to a novel semiconductor device manufacturing apparatus capable of effecting plural processes by utilizing photo-assisted reactions within a single chamber.
In a photo-assisted process, by selecting appropriate gaseous reactants and a light source of an appropriate wave length, there are induced a gas phase reaction of gaseous reactant molecules, reaction of adsorbed species and wafer, heating of wafer, etc. and there can be performed film deposition onto wafer, etching, impurity doping into film and cleaning of the wafer surface.
McWilliams et al have combined various gaseous reactants with an argon ion laser and performed plural processes at a raised temperature by moving a substrate while focusing an argon ion laser light on the surface of the substrate, thereby formed a MOS transistor [Bruce M. McWilliams et al., Appl. Phys. Lett. 43 (10, 946 (1983)].
According to the above technique, however, light emitted from the argon ion laser which is the only light source heats a limited part of the wafer and the gaseous reactants present near the wafer are thermally decomposed by that heat to form a film. Thus, the light acts on the gaseous reactants indirectly; in other words, a direct effect of light on the gas molecules in the gas phase and adsorbed species is not utilized at all and the characteristics of a light-assisted process are not fully utilized. For example, according to the above technique, it is impossible to process the whole surface of the wafer because a finely focused laser beam is used. Moreover, measures are not taken against the adhesion of gas used in the preceding step to the wafer and the inner wall of the reaction chamber.